1. Field of the Invention
The present invention relates to a switching power supply.
2. Related Background Art
A conventional switching power supply appears in Japanese Patent Publication No. 2,629,999, for example. The switching power supply of Japanese Patent Publication No. 2,629,999 has two output transformers connected thereto. In the first output transformer, two primary side coils are disposed with the same polarity on the same magnetic path and one of the primary side coils in the first output transformer and one of the primary side coils in the second output transformer are switched by means of a first driver circuit and the other primary side coil in the first output transformer and the other primary side coil in the second output transformer are switched by means of a second driver circuit, which provides the stability of the switching power supply. The secondary side coil of the transformer is connected to a rectifier circuit and a smoothing circuit, whereby the desired DC voltage is output.
In addition, inventions relating to a parallel drive power supply device by the present applicant appear in Japanese Patent Application Laid Open No. 2006-14535, Japanese Patent Application Laid Open No. 2006-20410, Japanese Patent Application Laid Open No. 2005-086846, and Japanese Patent Application Laid Open No 2005-086948, and these devices achieve superior operations.
However, there have been cases where the output is destabilized, such as a case where the characteristic of the choke coil contained in the smoothing filter varies from product to product.